Media

First of all. If you want to know what I’m up to next, follow me on twitter: @eirikso

So, I posted this video on YouTube two days ago:

And it have gone completely viral. It was made in a hurry and leaves a lot of things that might need an explanation.

The place and the moose

The video was shot just outside of Oslo. We have a lot of moose roaming around the woods here in Norway. And some of them very close to the city. They’re shy of people, dogs and other living creatures, but are pretty used to the sound of cars, trains, helicopters, planes etc. To see a moose is not very uncommon in Norway.

This moose is probably a 1,5 year old female. She seems more curious than afraid. And we spotted her again from far up in the sky later. Still calmly walking around eating in the same wood.

The technology in general

One of my hobbies for the last year have been to build and fly multirotor helicopters. When I fly them I do it either by flying Line-Of-Sight (LOS) or First Person View (FPV). When flying LOS you simply take off and fly the thing around while watching it from the ground. For quadcopters this limit the range because the copter is symmetric and you loose the orientation pretty fast. However, as I’ve gained experience you start to feel the direction based on speed and the way you control the copter, making it possible to fly further away. I fly LOS when I want to do acrobatics and train accuracy and pilot skills. Here is an example of some acro flying with a very small quadcopter:

But for the video with the moose I fly FPV. Meaning that I have a dedicated camera connected to a video transmitter on board the copter. I feed the video signal into a pair of video goggles and navigate the copter like I was sitting inside it. Based on the video signal. When flying this way I always have spotters beside me that keep an eye on the copter and what is happening on the ground.

In addition to the goggles I have a screen and a digital recorder on the ground station. That recorder also has a mic and records the audio from the spot where we are standing. Ensuring that we got the recording of the quite enthusiastic spotters and my rather nervous comments about battery status and the fact that it is darn difficult to navigate this thing between and under the trees.

The camera

On the copter there is also a GoPro Hero3 to record HD video on board. The video downlink is only SD-quality. In the video I cut to the footage from the DVR at some points to show how it looks from my goggles. Here’s a screen shot from that feed:

You can see the battery status in the top left corner. We spotted the moose at the end of my flight. At 13,2 volts the batteries will be harmed and the copter will descend automatically or simply crash.

Because the HD footage is done in the GoPro on board the copter it was pretty important for us to get it back in one piece. On this copter the GoPro is mounted “naked” without the water proof box. To save weight and make the mounting easier. So I don’t want to crash it in the snow.

The recording in the GoPro is 2,7 K @ 25 FPS. It is slightly stabilised in FCPX and rendered at 1920×1080.

The details

It is a quad rotor helicopter. Based on a X468 frame that makes it possible to wrap it together for easy travelling. It is controlled by a DJI Naza flight controller that has gyros, accelerometer, barometer and GPS to assist the stabilisation of the copter.

I am using an old Futaba 9C remote with FrSky Tx and Rx modules.

After my previous post about the copter I have changed to three blade, nine inch props (9x5x3). They give me less jello and vibrations in my recordings. In general I find it easier to get rid of vibrations with smaller props running at higher speed. So I run the copter on 4S batteries. Usually two 2200 mAh in parallel. That gives me up to 12 minutes flight time with GoPro and FPV equipment. But 12 minutes is with completely new batteries and when I am pushing the limit. Usually I fly around 8 minutes and land when my batteries are close to 14V. In this video I push it all the way down to 13,2 V when I land.

I have also changed the ESCs on the copter. From Turnigy Plush that I mention in the article about the copter to HobbyKing F30A with SimonK-firmware. That change made the copter way more stable.

Sony RX100

I am also flying this copter with a Sony RX100. It is heavier than the GoPro, giving slightly lower flight time. But the RX100 has excellent image stabilisation built in and you get rid of the GoPro fisheye-look. Here is a RX100-video from the same copter and same area.

The dangers

Multirotors can be dangerous. The props are spinning fast. And they might cut your skin if you get too close when they are running. On my copter I have pretty soft and cheap GWS props. They’re not as dangerous as the carbon reinforced props that many people use. But if you are flying high the pure weight of the copter is dangerous if it falls down. And they do. That is why we are flying outside of the city over fields with no people. And always have spotters on the ground when we fly FPV.

The lipo batteries are very powerful. And can explode or catch fire if they are damaged.

In addition to this there are rules regarding remote controlled devices. They are different in different countries. In Norway you can fly up to 400 feet. And you need a special license to be allowed to put a camera on anything that flies.

If you want to to professional AP work you need an extra license from the civil aviation authority.

The fun and the problem

Lots of people immediately say “I want one” when they see how fun this is. And I can really recommend this hobby. But you need to be patient. First of all it is very difficult to fly these things. It has taken hours and hours of training to be able to fly the way I do in this video.

And even more hours fixing the broken copter after crashing. That is why I build them myself from the ground up. For the first couple of months I never returned with empty batteries. I always returned with a broken copter.

To start training I can really recommend this small and harmless copter: WLtoys V929. It is a toy, but it is four channel and is controlles just like the bigger copters. If you learn to fly this thing it will be easier to fly bigger and more dangerous copters.

Just recieved my KK2 Flight controller from HobbyKing. I planned to put it in one of my existing quads, but figured I had four ESCs and four motors lying around. So I could just as well build a new quad for it. The only thing I needed was a frame.

So I found a bottle of Amarone, made a good meal, had a nice dinner and made a quad frame out of the box where the bottle of Amarone used to be:

Update:
I crashed the Amarone-frame so many times that I ran out of spare parts. I have now moved the parts to this carbon frame.

I also managed to destroy the KK2-controller. While waiting for a new one I’m experimenting with a baseflight-flashed FreeFlight controller and a Rabbit on this small quad. Both seems to work well. The FreeFlight is not available anymore, but with baseflight/MultiWii it is basically a very bulky Naze32 with less sensors. So, buy the Naze32 if you want a very good MultiWii based FC.

Conclusion about the KK2-controller

Very easy to set up. Love the fact that you can debug and adjust right there on the FC thanks to the LCD. Very stable rate mode but too sluggish auto level. I really hope Rolf Bakke have the time to implement the AHRS algorithm that utilize both the accelerometer and the gyro when in auto level mode. Right now the auto level mode is only good for slow hovering and maybe some help if you loose orientation.

But as you can see from the video in this article. That $30,- board makes my micro quad built from cheap parts steady as a table and loads of fun to fly!

And the Amarone-frame? Takes a lot of beating, but I managed to crash it bigtime.

Luckily I had some spare parts from the same wine bottle box so I managed to fix it and make it even better…

Did a quick test during easter. Mounted my FPV equipment on a 1/10-scale RC car and had some fun. Lots of fun!

This was roughly what I saw in the goggles. (No, not that quality, this is a HD recording from the GoPro on the car.)

FPV what?

FPV is “first person view”. The art of mounting a camera and a video transmitter on remote controlled equipment. Then you sit down with some video goggles and the remote control. And drive the car based on the video feed. It gives you an amazing feeling of sitting inside the vehicle you are controlling. Like a video game. But in real life.

Fun when controlling RC planes and helicopters. But also fun (and much safer) when controlling RC cars!

Equipment:

If you want to snap images or record video from your quadcopter it needs to be as vibration free as possible. When you manage that you get shots like these:

But when you start googling you get the same answer all over:

1. Balance your propellers
2. Balance your motors

But I did that:

And I still had vibrations, blurry stills and jelly-looking video. After a lot of trial and error found the solution.

It doesn’t matter how much you balance your props if they’re the wrong props. You need high quality very stiff props for aerial photography (AP). So, on the same quad, with perfectly balanced props I had lots of vibrations with one set of props and no vibrations with another.

I have had best results with Gaui props and Graupner E-props.

In addition to this I made a dampening system. First I tried to mount the camera directly on a small plate that was mounted on the quad with rubber dampers. That din’t work very well:

(Dampers = red)

Then I made a long extra board under the quad. Mounted it to the quad using four rubber dampeners and mounted both the camera and the battery on that one. Wow! No vibrations with any of my cameras!

(Dampers = red)

Update:
And this is how video looks like if you don’t limit the vibrations.

The SX230HS is small enough to be way more practical than the 5D for certain trips. And good enough to be worth carrying in addition to the camera already in the iPhone.

But I also need the speed and simplicity of publishing that the camera in the phone gives me. So I was plesantly surprised when I could conclude that my EieFi-card talks directly to my phone when the personal hotspot is activated.

If I run ShutterSnitch on the phone while the hotspot is active it happily receives images directly from the camera when I turn it on.

There are some issues with a lost connection after some inactivity but I’ll keep experimenting.

The images in this post are snapped with the SX230HS, transferred directly to the phone, edited and and added to the article. Everything on the go.

I’m currently working on a new time lapse project. Not a sort-of-time-lapse. But a true one. To put it short: I’ve had an SLR camera in my window at the same spot for one year. Snapping an image every half hour. Resulting in some pretty nice time lapse videos I’ll post here in a couple of days. But first a still image.

The resolution of the 16 000 images I now have from 2010 are 3888×2592 pixels. So I selected 3888 images snapped during the day. Then I got some generous help from my blog readers and twitter followers. To make a script that would take one line from the first image, the next line from the next image and so on. Jo Christian Oterhals, Nikolai Kristiansen and Aslak Hellesøy provided complete code for the solution.

It shows one whole year. January at the left and December to the right. You can clearly see that we have a pretty long winter and a decent summer here in Oslo, Norway.

The spring and autumn are both quite short.

It would have been nice to make an interactive version of this image. Where you could mouse over and get info on exactly when the image providing the line was taken. And maybe also bring up a thumbnail of the complete image. Maybe I’ll post all the 3888 images and hope that someone will make a solution like that…

The diversity

Light and timing are some of the most important factors in an image. I have huge amounts of images snapped at the exact same spot. With the exact same focus point and the same f-number. The only thing that have changed is the season and the light. Bringing diversity like this: